A stamp envelope is desirable to protect stamps from soiling and to organize them in a practical way when being stored in drawers, briefcases and hand bags. The envelope may provide informative postal information for first class, overweight, oversized items, postcards and international rates and to help identify appropriate mail size limitations.
The envelope must require a minimum of materials and be simple to assemble. It should be possible to construct the envelope from a single sheet of continuous material but be able to vary the maximum distance between the front and rear of panels when in an open condition.
Representative prior art envelopes are disclosed in the E. V. Hudson U.S. Pat. No. 1,131,135, Mar. 9, 1915 and H. Rueve, Jr., U.S. Pat. No. 763,797, Jun. 28, 1904.
The shortcoming of the prior art envelopes is that there is no simple, inexpensive way of varying the maximum distance between the front and rear walls when in an open condition without constructing the end walls from pieces of material separate from the front end rear walls. Thus, what is needed is an envelope and method of making same that readily allows for constructing the envelope with a variable access opening into the storage chamber between the front and rear panels while utilizing a single sheet of material.